The strongest are ionic. Charges go from one atom to another, and then the two atoms are attracted by the electric forces.

 

The next weaker bond is covalent. Here the atoms share electrons.

 

Other types of bonds are the bonds holding metals and glasses together.

 

The weakest is the van der Waals. It is the force that makes things sticky. We do not discuss this force in class, but it is important that at least you be aware of it.

 

In summary, do not think that there are only two types of bonding: ionic and covalent.